setup.sh: ensure docker group exists and apply membership immediately

add sudo groupadd docker to README docker-group setup steps
run newgrp docker in setup.sh after usermod -aG docker $USER
so group changes take effect in the current session

Signed-off-by: Anurag Pateriya <apateriy@qti.qualcomm.com>

Author: apateriy-qcom

README.md

@@ -21,6 +21,7 @@ https://docs.docker.com/engine/install/ubuntu/#install-using-the-repository
 
 ### Add user to the docker group
 ```
+sudo groupadd docker
 sudo usermod -aG docker $USER
 newgrp docker
 ```

setup.sh

@@ -77,6 +77,7 @@ fi
 echo "Adding current user to docker group..."
 sudo groupadd docker || true
 sudo usermod -aG docker $USER
+newgrp docker
 
 echo "Building Docker image..."
 docker build --build-arg USER_ID=$(id -u) --build-arg GROUP_ID=$(id -g) --build-arg USER_NAME=$(whoami) -t kmake-image .